Apparatus for the mechanical production of acoustic vibrations



. Jan. 22 1963 E c. OTTELL ETA Re. 25,324

ARATUS FOR THE. MECHAN L PRODUCTION O COUSTIC VIBRATIONS FOR USE INEMULSIFICATION, DISPERSION OR LIKE PROCESS Original Filed July 15, 1952Er/c C. Cazfl/ John E'. Goodman m United States Patent Ofiice Re. 25,324Reissued Jan. 29, 1963 Claims. (Cl. 2591) Matter enclosed in heavybrackets appears in the original patent but forms no part of thisreissue specification; matter printed in italics indicates the additionsmade by reissue.

This invention relates to apparatus for the mechanical production ofacoustic vibrations generally in the ultrasonic range in a mannersuitable particularly for use in the emulsification or homogenisation ofoil and water and suspensions of solid matter in liquids and likepurposes.

The apparatus makes use of the known principle of mechanical productionof ultrasonic or like acoustic vibrations which is used in a liquidwhistle and which consists essentially in causing a jet of liquid toimpinge on a vibratory member so as to produce high frequencyvibrations, but applies this principle in a practical arrangementcapable of being put to numerous industrial uses and particularly in areadily portable form.

According to the invention the apparatus consists in a jet-formstructure to which liquid can be supplied under pressure and having oneor more restricted outlets or nozzles which direct the liquid streamagainst a blade or like vibrator so as to produce acoustic vibrationsgenerally in the ultrasonic range, the jet-form structure and vibratorbeing mounted so as to be readily introduced into or close to the mediumto be treated.

Preferably a blade or other form of vibrator is mounted on the jet-formstructure which in turn is mounted on the end of the fiuid supply pipeor in a frame or on arms and such pipe, frame or arms can be adapted forfixing upon a vessel which is to contain the medium to be treated or canbe swung into and out of working position as desired.

In order that the invention may be clearly understood and readilycarried into effect the same will now be more fully described withreference to and by the aid of the accompanying drawings, wherein:

FIGURES 1 and 2 are respectively an elevation and plan of one form ofportable apparatus according to the invention shown mounted on the sideof a mixing pan.

FIGURE 3 is an elevation mainly in section of the body of the jet-formstructure.

FIGURE 4 is an elevation of a bell-like nose piece forming the outer endof the jet-form structure.

FIGURE 5 is a plan of the body shown in FIGURE 3.

FIGURE 6 is a transverse section taken on the line AA in FIGURE 5showing the detail of the jet-form outlet.

In the illustrated embodiment of the invention a rotary pump 1 andelectric motor 2 are mounted as a unit in a casing from which dependsuction and delivery pipes 3, 4. The lower end of the delivery pipe 4has connected to it the jet-form structure which may be moulded in asuitable synthetic material or cast in suitable metal.

This jet-form structure is shown as consisting of a body in halves 5, 6with an outer covering 7, or alternatively the two halves can be boltedtogether, the body being connected at the inner end by a union 8 to thedelivery pipe 4 and having an internal passage 9 which is circular atits inner end and gradually flattens out in smooth contours towards theouter end where it forms a slit like outlet 10. This outlet 10 may varysomewhat in shape, but as illustrated its section is represented by theintersection of two circles of the same radius which radius is such thata straight line joining the two points of intersection is in the ratioof 50:1 relative to the height of the rightangular upright drawn fromthe centre of such line to the circumference of one circle. With thedimensions w and t indicated in FIGURE 6, the diameter of each circlewould be represented by W2 Inv any event the shape of outlet will bedesigned with the object of producing a jet of liquid best adapted tocooperate with the vibratory blade.

The blade 11 is preferably made of spring steel of the shape illustratedwith a hollow ground edge on which the liquid jet impinges. This bladeis clamped by narrow strips and screws 12 to two arms 13 formed with orsecured to the body half 6, so that the blade is free to vibrate at itsown frequency without support along its sharpened edge.

A resonant hell or nose piece 14 can be screwed onto the threaded endsof the body halves to surround the blade and its mounting, and this bellhas its internal bore reduced to form an open circular end 15 of adiameter approximately equivalent to the length of the jet-form outlet10. By this means the efiect of the vibration may be amplified and acavity maintained in the bell by the ejector eflfect of the liquidpassing at high speed across the blade and through the bell. This maymaintain the velocity of the jet across the blade at a faster rate thanif it were immersed in the liquid without the bell attached, owing tothe inertia of the liquid itself slowing down the jet when it is notpassing through the bell.

The casing of the motor 2 is shown with a swivel bracket 16 by which thewhole apparatus can be pivotally mounted on the side of a pan or likevessel 17 to contain the liquid to be treated and this bracket caninclude readily detachable clamping means to enable the apparatus to bemoved at will. The apparatus can be counterbalanced by suitable means(not shown) so as to be readily lowered into the vessel. Alternativelythe apparatus would be arranged for suspending above the vessel andlowering into it.

It is intended generally to operate the apparatus with the outlet andblade below the liquid level in the vessel, though it may operate justabove the surface with the suction pipe 3 dipping below.

When operating with the apparatus the mixture is drawn into the pump andthen expelled through the jetform outlet at a pressure (say) of from to300 lbs., per square inch, impinging on the blade and deflecting it. Theelasticity of the blade itself restores it to its normal position and itis again deflected in the opposite direction. This cycle continues atvery high speed and ultrasonic oscillation results. Cavitation at theblade tip causes violent agitation of the liquid and consequentemulsification or such like due to very high pressures realised on thecollapse of the cavities.

The pump can be provided with a by-pass to vary its capacity and,therefore, the pressure and intensity of the oscillations produced.

As an alternative a thick blade of concave wedge or other shape may bemounted on a torsion bar which would allow the blade to vibrate althoughtoo thick to oscillate due to its own elasticity. In such case therewould be less likelihood of the blade breaking through fatigue.

It is believed that an apparatus according to the invention will be ofmore simple and compact construction than any at present employed inindustry and may have an extensive application in the pharmaceutical,cosmetic,

3 textile, food, mineral preparation, brewing, oil, engineering andother industries.

Practical tests indicate that the apparatus will absorb only a smallfraction of the power needed by equivalent emulsifiers of conventionaltypes and its efiiciency will enable less emulsifying agent to be usedand produce a very finely divided suspension.

We claim: 1

1. Apparatus for producing emulsification or homogenisation of oil andWater and suspensions of solid matter in liquids and like purposes bymechanically produced acoustic vibrations in or near the ultrasonicrange, comprising in combination a jet-form structure having at leastone restricted outlet or nozzle, a blade-like vibrator element having atleast a portion thereof supported for vibratory movement and locatedwith its thin edge in line with said outlet, a resonant bell or nosepiece fixed at one end to the jet-form structure and surrounding saidblade like vibrator element and having an opening in its other end,means for passing the liquid to be treated under pressure through saidjet-form structure andagains't the thin edge of said vibrator element soas to produce the acoustic vibrations, and means for introducing saidjet-form structure and vibrator element into or close to the medium tobe treated. l

2. Apparatus for producing emulsification or homogenisation of oil andwater and suspensions of solid matter in liquids and like purposesbymechanically produced acoustic vibrations in or near-the ultrasonicrange, comprising in combination a jet-form structure having at leastone restricted outlet or nozzle, a blade-like vibrator element having atleast a portion thereof capable of vibratory movement and mounted onsaid structure with its thin edge in line with said outlet, a resonantbell or nose piece fixed at one end to the jet-form structure andsurrounding said blade-like vibrator element and having an opening inits other end, means for passing the liquid to be treated under pressurethrough a delivery pipe on which said structure is mounted and throughsaid structure and against the thin edge of said vibrator element so asto produce the acoustic vibrations, and means for supporting saiddelivery pipe, jet-form structure and vibrator element in connectionwith a vessel which is to contain the medium'to be treated so as to becapable of readily being moved into and out of Working position.

3. Apparatus as called for in claim 2, including a jetform structurehaving an internal passage which changes by smooth contours from asubstantially circular inlet at the inner end to a slit-like outlet atthe outer end, and a vibratory blade located substantially in the planeof said s1it-like outlet so as to receive the jet of liquid against itsfree edge.

4. Apparatus as called for in claim 2, including a jetform structurehaving an internal passage which changes by smooth contours from asubstantially circular inlet at the inner end to a slit-like outlet atthe outer end, and a vibratory blade located substantially in the planeof said slit-like outlet so as to receive the jet of liquid against itsfree edge and wherein said resonant bell or nose piece is fixed atoneend to the outer end of said jet-form structure and has a circularopening in its other end of a diameter approximately equivalent to thelength of said outlet. [and a resonant bell or nose piece applied to theouter end of said jet-form structure and surrounding said blade and itsmounting and having a circular opening in its outer end of a diameterapproximately equivalent to the length of the jet-form outlet] 5.Apparatus for producing emulsification or homogenisation of oil andwater andsuspensions of solid matter in liquids and like purposes bymechanically produced acoustic vibrations in or near the ultrasonicrange comprising in combination an electric motor and a pump driventhereby mounted as a unit, a suction pipe and a delivery pipe connectedto and supported from said pump, a jet-form structure mounted on theouter end of said delivery pipe and having an internal passage whichchanges by smooth contours from a substantially circular inlet at theinner end to a slit-like outlet at the outer end, a thin vibratory bladeclamped by its thicker edge to two arms projecting forwards from saidjet-form structure and located with its sharpened edge opposite andparallel to said slit-like outlet so as to be vibrated by the liquid jetimpinging on it, a resonant bell or nose piece applied to the outer endof said jet-form structure and surrounding said blade and its mountingand having a circular opening in its outer end of a diameterapproximately equivalent to the length of said slit-like outlet, anddisengageable means for supporting the complete apparatus in connectionwith a vessel to contain the liquid to be treated with the suction pipedipping into said liquid and for enabling said apparatus to be loweredinto and raised out of working position.

References Cited in the file of this patent or the original patentUNITED STATES PATENTS 1,445,427

(from Paint Manufacture, May 1951, vol. XXI, No. 5, pages 157-161 and175).

